Unclassified sex cord/gonadal stromal testis tumor with a "pure" spindle cell component: a case report.

Unclassified sex cord/gonadal stromal tumors (SCSTs) composed predominantly of spindle cells are rare. Very few cases have been documented to date. Here, we report a case of "pure" spindle cell tumor of the left testis in a 83-year old man whose morphological and immunohistochemical findings were consistent with a diagnosis of unclassified SCST and review the literature. Owing to the spindle cell pattern, the differential diagnosis with other benign and malignant spindle cell lesions is discussed.